Network Working Group J. Heafner
Request for Comments: 227 E. Harslem
NIC: 7631 September 17, 1971
Updates: RFC 113
DATA TRANSFER RATES (RAND/UCLA)
The attached memo indicates data rates typical of our use of RJS at
UCLA CCN. Earlier timing tests (similar but more detailed) with UCSB
showed that most of the time was lost because of: (1) channel
contention with our disk drive access; (2) our NCP runs at a higher
priority than batch jobs but lower than text editing and interactive
graphics; (3) OS interrupt handling is very slow on both ends; (4)
spooling time of the remote system.
MEMORANDUM
TO: John Heafner
FROM: Bob Hoffman
COPIES: Bob Mobley, Herb Shukiar
Here are some of the transmission rates I have noted over the network
between Rand and UCLA. These were all taken at night when little else
was happening on our 65.
SEND TO UCLA
# Cards Blocksize (bytes) Time (secs) Rate (bits/secs)
642 80 50 8218
375 80 30 8000
509 800 20 16288
RECEIVE FROM UCLA
For all figures below, the receiving file has blocksize of 1330
bytes, and each line is assumed to contain 100 bytes. This last
assumption is fairly accurate, since most of the lines were from PL/I
for which this is a very good number. Thus, for each rate, the
number of bytes is the # Lines * 100.
# Lines Time (secs) Rate (bits/secs)
4900 200 19600
872 47 14843
3900 185 16865
Heafner & Harslem [Page 1]
RFC 227 DATA TRANSFER RATES (RAND/UCLA) September 1971
As you can see from the send figures, blocking makes about a 2:1
difference. Memory also recalls a 2 or 3 to 1 advantage for blocking
on receive when we were getting unblocked files from UCSB.
REH:gb
[This RFC was put into machine readable form for entry]
[into the online RFC archives by Kelly Tardif, Viagénie 10/99]
Heafner & Harslem [Page 2]